It's the top of pitch #1 jeezs no other belay on the entire climb has a lost arrow piton as part of the belay setup.

For this to be pitch #3 you would have to have started in the creek or I know maybe you started on grad boulder set up a zipline across the creek roped up for the -1st class scree ascent to the sub class 4 slab start belayed again here than proceeded to the aforementioned p3 belay cool.....